Chuck assembly for a drill, a drill tool, and drill bit member for use in association with a chuck assembly

ABSTRACT

A central chuck including a chuck base, a first chuck and a first drill bit. The first chuck is rotatably coupled to the chuck base and has a chuck bore terminating at a lower chuck wall and a transverse locking bore. A locking plug is threaded into the transverse locking bore. The first drill bit has an upper portion, a central portion and a distal end. The upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder. Threaded insertion of the locking plug into the chuck bore interfaces with the drill bit and directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Patent Application Ser. No. 62/971,929 filed on Feb. 8, 2020, entitled “SYSTEM AND METHOD FOR COUPLING FASTENER HARDWARE TO A BRACKET”, and claims priority from U.S. Provisional Patent Application Ser. No. 63/031,882 filed on May 29, 2020, entitled “SYSTEM AND METHOD FOR COUPLING FASTENER HARDWARE TO A BRACKET”, the entire disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The disclosure relates in general to drilling equipment, and more particularly, to a chuck assembly for a drill and a drill bit member for use in association with a chuck assembly.

2. Background Art

The formation of openings in materials, such as brackets or the like, is well known in the art. Typically, a drill bit is coupled to a drill chuck and as the drill bit is rotated, force is applied to drive the drill bit to form a hole, an opening, or such structures in the underlying material.

In some instances, the drill is extending fully through the material so that the depth is not much of a concern. In other configurations, a chamfer or countersink is formed at the upper end of the opening. In some such operations, the depth and/or shape of chamfer or countersink is highly significant. One such application is in the attachment of fastener hardware to brackets to make aviation components (while the disclosure is not limited thereto). In such instances, the position of the drill bit in the chuck becomes very important. Additionally, in some such configurations, a pair of chucks are positioned in side by side configurations, each having a drill bit, wherein, a pair of openings are simultaneously formed. In such instances, both of the drill bits are configured to form the countersink or chamfer with precision.

Problematically, it is in many instances difficult to precisely attach the drill bit to the chuck to achieve the desired depth. Even tightening of the chuck can result in slight shifting of drill bits within the tightening chuck. Where there are multiple chucks that have drill bits which simultaneously form openings, having the two chucks (which move in unison) with drill bits that are not positioned in correspondence can result in pairs of openings, wherein one of the pairs is not properly formed.

SUMMARY OF THE DISCLOSURE

The disclosure is directed, in a first aspect to a central chuck comprising a chuck base, a first chuck and a first drill bit. The first chuck is rotatably coupled to the chuck base. The first chuck has a chuck bore, a transverse locking bore and a locking plug. The chuck bore terminates at a lower chuck wall. The transverse locking bore extends transversely into the chuck bore spaced apart from the lower chuck wall. The transverse locking bore is threaded. The locking plug is threaded into the transverse locking bore. The locking plug thread terminates at a distal end. Rotation in a first direction advances the locking plug thread into the bore. Rotation in a second direction retreats the locking plug thread from within the bore. The first drill bit has an upper portion, a central portion and a distal end. The upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane is defined in the upper portion inclined in a downward and inward direction toward the shoulder. Upon insertion of the upper portion of the first drill bit into the chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond. The distal end of the locking plug is directable at and into contact the oblique plane. Further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.

In some configurations, a second chuck rotatably coupled to the chuck base. The second chuck has chuck bore, a transverse locking bore and a locking plug thread. The chuck bore terminates at a lower chuck wall. The transverse locking bore extends transversely into the chuck bore spaced apart from the lower chuck wall. The transverse locking bore is threaded. The locking plug is threaded into the transverse locking bore. The locking plug thread terminates at a distal end. Rotation in a first direction advances the locking plug thread into the bore. Rotation in a second direction retreats the locking plug thread from within the bore.

Further, a second drill bit is provided that has an upper portion, a central portion and a distal end. The upper portion of the second drill bit has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane is defined in the upper portion inclined in a downward and inward direction toward the shoulder.

As with the first drill bit, insertion of the upper portion of the second drill bit into the second chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond. The distal end of the locking plug is directable at and into contact the oblique plane. And. further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.

In some configurations, the lower chuck wall of the first chuck and the lower chuck wall of the second chuck are coplanar.

In some configurations, each of the first drill bit and the second drill bit are substantially identical. The first drill bit and the second drill bit each include a chamfer or countersink formed between the central portion and the distal end.

In some configurations, the first drill bit further includes a chamfer or countersink formed between the central portion and the distal end.

In some configurations, the oblique plane of the first drill bit is angled relative to a plane tangent to an outer surface of the upper portion in an inward and downward direction toward the shoulder at an angle of between approximately 3° and 17°. In some such configurations, the angle is approximately 4° and 12°, and more preferably approximately 6° and 9° and more preferably between 7° and 8°.

In some configurations, each of the upper portion and the central portion of the first drill bit comprise cylindrical configurations that are concentric.

In some configurations, the shoulder is perpendicular to a longitudinal axis of the first drill bit.

In another aspect of the disclosure, the disclosure is directed to an upper drill tool comprising a central chuck, an upper component, a lower component and a coupling assembly. The central chuck comprises a chuck base, a first chuck and a first drill bit. The first chuck is rotatably coupled to the chuck base. The first chuck has a chuck bore, a transverse locking bore and a locking plug. The chuck bore terminates at a lower chuck wall. The transverse locking bore extends transversely into the chuck bore spaced apart from the lower chuck wall. The transverse locking bore is threaded. The locking plug is threaded into the transverse locking bore. The locking plug thread terminates at a distal end. Rotation in a first direction advances the locking plug thread into the bore. Rotation in a second direction retreats the locking plug thread from within the bore. The first drill bit has an upper portion, a central portion and a distal end. The upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane is defined in the upper portion inclined in a downward and inward direction toward the shoulder. Upon insertion of the upper portion of the first drill bit into the chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond. The distal end of the locking plug is directable at and into contact the oblique plane. Further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.

The upper component is coupled to the central chuck and has a lower stop surface. The lower component has a central body and an outer ring. The central body has an outer surface with threads disposed thereon. The central body has a drill bit bore corresponding to each of the at least one chuck, to facilitate the passage of the drill bit therethrough. The bore terminates at a lower end of the central body. The outer ring has an inner surface with outer ring threads positioned thereon. The outer ring threads matingly engaging the threads of the central body. The outer ring has an upper stop interfaceable with the lower stop surface of the upper component. The coupling assembly has a slidable coupling having a first end attached to the lower component and a second end attached to one of the central chuck and the upper component. The slidable coupling facilitates the slidable movement of the lower component from a first orientation wherein the upper stop is spaced apart from the lower stop surface and a second orientation wherein the upper stop is in abutting engagement with the lower stop surface. The first orientation and the second orientation define a stroke.

In some configurations, a second chuck rotatably coupled to the chuck base. The second chuck has chuck bore, a transverse locking bore and a locking plug thread. The chuck bore terminates at a lower chuck wall. The transverse locking bore extends transversely into the chuck bore spaced apart from the lower chuck wall. The transverse locking bore is threaded. The locking plug is threaded into the transverse locking bore. The locking plug thread terminates at a distal end. Rotation in a first direction advances the locking plug thread into the bore. Rotation in a second direction retreats the locking plug thread from within the bore.

Further, a second drill bit is provided that has an upper portion, a central portion and a distal end. The upper portion of the second drill bit has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane is defined in the upper portion inclined in a downward and inward direction toward the shoulder.

As with the first drill bit, insertion of the upper portion of the second drill bit into the second chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond. The distal end of the locking plug is directable at and into contact the oblique plane. And. further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.

In yet another aspect of the disclosure, the disclosure is directed to a drill bit for use in association with a central chuck. The drill bit has an upper portion, a central portion and a distal end. The upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion. An oblique plane is defined in the upper portion inclined in a downward and inward direction toward the shoulder.

In some configurations, the drill bit further comprises a chamfer or countersink formed between the central portion and the distal end.

In some configurations, the oblique plane of the first drill bit is angled relative to a plane tangent to an outer surface of the upper portion in an inward and downward direction toward the shoulder at an angle of between approximately 3° and 17°. In some such configurations, the angle is approximately 4° and 12°, and more preferably approximately 6° and 9° and more preferably between 7° and 8°.

In some configurations, each of the upper portion and the central portion of the first drill bit comprise cylindrical configurations that are concentric.

In some configurations, the shoulder is perpendicular to a longitudinal axis of the first drill bit.

In some configurations, the distal end has a diameter that is smaller then a diameter of the upper portion.

In some configurations, the oblique plane terminates at the shoulder and initiates spaced apart from an upper end of the upper portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will now be described with reference to the drawings wherein:

FIG. 1 of the drawings is a perspective view of the system having a drill portion and a fill portion;

FIG. 2 of the drawings is a drill portion having the upper drill tool and lower drill tool of the present disclosure;

FIG. 3A of the drawings is a perspective view of a bracket having a hardware coupled thereto with a fastener;

FIG. 3B of the drawings is a perspective view of the hardware shown in FIG. 3A;

FIG. 3C of the drawings is a perspective view of a rivet utilized to couple the hardware to the bracket;

FIG. 4 of the drawings is perspective view of the upper drill tool and lower drill tool of the present disclosure;

FIG. 5 of the drawings is a perspective view of the upper drill tool and lower drill tool of the present disclosure with the housing cover removed from a portion of the lower drill tool;

FIG. 6 of the drawings is a front elevational view of the upper drill tool and lower drill tool;

FIG. 7 of the drawings is a front perspective view of the upper drill tool of the present disclosure;

FIG. 8 of the drawings is a back perspective view of the upper drill tool of the present disclosure;

FIG. 9 of the drawings is a perspective cross-sectional view of the upper drill tool of the present disclosure, showing the drill tool in the first orientation (or away from the second orientation);

FIG. 10 of the drawings is a perspective cross-sectional view of the upper drill tool of the present disclosure, showing the drill tool in the second orientation;

FIG. 11 of the drawings is a cross-sectional view of the upper drill tool of the present disclosure, showing the drill tool in the second orientation;

FIG. 12 of the drawings is a partial perspective view of the upper tool, showing, in particular the first and second chucks along with an upper part of the first and second drill bits;

FIG. 13 of the drawings is a side elevational view of a drill bit of the present disclosure;

FIG. 14 of the drawings is a partial side elevational view of the drill bit of FIG. 13, showing, in particular, the upper portion and central portion of the drill with the shoulder and oblique plane; and

FIG. 15 of the drawings is a partial perspective view of the drill bit of FIGS. 13 and 14, showing, in particular, the upper portion and central portion of the drill with the shoulder and oblique plane.

DETAILED DESCRIPTION OF THE DISCLOSURE

While this disclosure is susceptible of embodiment in many different forms, there is shown in the drawings and described herein in detail a specific embodiment(s) with the understanding that the present disclosure is to be considered as an exemplification and is not intended to be limited to the embodiment(s) illustrated.

It will be understood that like or analogous elements and/or components, referred to herein, may be identified throughout the drawings by like reference characters. In addition, it will be understood that the drawings are merely schematic representations of the invention, and some of the components may have been distorted from actual scale for purposes of pictorial clarity.

Referring now to the drawings and in particular to FIGS. 1 and 2, the upper drill tool is shown generally at 10. In one application, the drill tool is configured to drill openings through a bracket, such as bracket 302 (FIG. 3A), while other uses are contemplated. In such a use, the upper drill tool 10 can be used in association with a lower drill tool, such as lower drill tool 11. With reference to FIG. 1, the upper and lower drill tool may be utilized in a larger system 500 which is configured with a drill portion 501 and a fill portion (i.e., riveting or joining portion) 502. The drill portion, also referred to as a drill system, generally provides for an upper portion to which the upper drill tool is coupled and moved vertically up and down toward and away from the lower drill tool. The upper portion may include motors and/or servos that can energize the chuck(s) (as will be described below) that are retaining the drill bit(s). The upper drill tool is not limited to use therewith.

In one instance, the upper drill tool is utilized in association with the preparation of openings in a bracket that can be utilized in the formation of structures utilized in aircraft structures. For example, these brackets (i.e., structural members such as beams or the like) can have hardware, such as hardware 300 (FIG. 3B), fastened to the bracket 302 utilizing rivets such as rivet 304 (FIG. 3C). The fastener hardware typically includes a base flange 310 having an upper surface 320 and a lower surface 322. A centrally located cylinder 314 extends from the upper surface 320 of the of the base flange and includes bore 315 extending therethrough. A pair of opposing rivet openings 312 are disposed on opposing sides of the centrally located cylinder. The bracket is coupled to fastener hardware which corresponding openings 412 and bore by extending rivets through the openings 312, 412 to couple the same together. To locate the openings, the bracket typically includes central opening 411 about which the openings for the rivets are drilled. It will be understood that a number of different configurations exist for the fastener hardware and the brackets. Additionally, it will be understood that the particular assembly of the present disclosure is not limited for use in association with such brackets, hardware or rivets.

The upper drill tool is not limited to use in association with the aviation industry, or in association with the drilling of openings through brackets, much less brackets of the type shown at bracket 302. The foregoing is meant to be exemplary and not limiting.

The upper drill tool 10 is shown, in greater detail, in FIGS. 4 through 8 as comprising, central chuck 12, upper component 14, lower component 16, and coupling assembly 18. The upper drill tool can be mounted to a movable structure such that the upper drill tool can be raised and lowered relative to a lower drill tool (FIG. 9) which may be fixed or movable). In the configuration shown in FIGS. 4 through 6 in greater detail, the upper drill tool can move linearly upwardly and downwardly toward and away from a lower drill tool 11.

The central chuck 12, in the configuration shown in FIGS. 9 through 11, includes a chuck base 20 and a plurality of chucks that are configured to retain multiple chucks to hold a drill bit in each. In the configuration shown, a total of two side by side, spaced apart chucks are disclosed, namely first chuck 22 and second chuck 24 (that may be gear driven from a single powered shaft, for example). A first drill bit 26 is attached to (or attachable to) the first chuck 22. Similarly, a second drill bit 28 is attached to (or attachable to) the second chuck 28. It will be understood that the two chucks can rotate in unison (in the same or opposite direction) and that the chucks can be raised and lowered together with the entirety of the upper drill tool attached to a movable structure. The drill bits include a distal end which may comprise a drill bit having a countersink so as to form an opening with a chamfer or a counter sink. Other drill bits are contemplated for use, however, the disclosure is particularly useful for the drilling of openings that include a countersink or chamfered opening.

In greater detail, and with reference to FIGS. 12 through 15, the first chuck 22 includes lower chuck wall 38, chuck bore 40 and transverse locking bore 41. The chuck bore 40 terminates at the lower chuck wall 38. A transverse locking bore extends transversely through the chuck spaced apart from the lower chuck wall. The transverse locking bore is threaded and terminates in the chuck bore 40. A locking plug 42 can be threaded into the transverse locking bore. The locking plug 42 terminates at the distal end 43. The distal end 43 protrudes into the chuck bore 40 wherein rotation of the locking plug in a first direction advances the distal end further into the chuck bore whereas rotation of the locking plug in a second direction retreats the distal end outwardly from the chuck bore.

The second chuck 24 has a similar configuration, wherein like components are identified with the same reference numbers augmented by a prime (′). It will be understood that the lower chuck wall 38 and the lower chuck wall 38′ are configured to correspond to each other and to be substantially coplanar with relatively tight tolerances the magnitude of which is largely determined by the tolerances required with the openings, as is understood to one of skill in the art.

The first drill bit 26 and the second drill bit 28 are substantially identical. The first drill bit 26 will therefore be described in detail with the understanding that the second drill bit is substantially identical. The first drill bit 26 includes upper portion 45, central portion 46 chamfer portion 49 and distal end 50. The upper portion 45, the lower portion 47 and the distal end 50 comprise concentric cylindrical members having varying diameters, with the diameter of the upper portion 45 and the distal end 50 being of a smaller diameter than the central portion 46. The chamfer or countersink 49 spans between the central portion 46 and the distal end 50, thereby defining the chamfer surface. It will be understood that the chamfer surface can be varied by varying the angle and the length of the chamfer (as well as the diameters of the central portion and the distal end). A shoulder 47 spans between the upper portion 45 and the central portion 46. The shoulder is substantially perpendicular to the longitudinal axis of the first drill bit 26.

In the configuration shown, the upper portion and the central portion comprise cylindrical members, while polygonal members are contemplated as well. It will be understood that such polygonal members may have in excess of 5 sides.

An oblique plane 48 is defined in the upper portion 45 and is formed by an intersection of a plane with the cylindrical upper portion that intersects obliquely. In the configuration shown, the oblique plane is at an angle wherein the oblique plane terminates short of the upper end of the upper portion 45, and is angled so that when the oblique plane intersects and terminates at the shoulder 47, the oblique plane does not extend to or beyond the longitudinal axis of the first drill bit. In the configuration shown, relative to a vertical line taken tangent to the outer surface of the upper portion, an angle of approximately 3° to 17°, and more preferably an angle of approximately 4° to 12° and more preferably an angle of approximately 6° to 9° and more preferably between 7° and 8° is defined. This angle may be varied depending on the application.

As with the description of the first drill bit, the operation of coupling the first drill bit to the first chuck will be described with the understanding that the second drill bit is coupled to the second chuck in substantially the same manner. As the first drill bit 26 is inserted into the chuck 22, eventually, the shoulder 47 reaches and abuttingly engages the lower chuck wall 38. Further insertion of the first drill bit into the first chuck is precluded and the end of insertion is reached.

Next, the user rotates the first drill bit so that the oblique plane is directed at the transverse locking bore 41. The locking plug 42 is threaded into the transverse locking bore 41 until the distal end 43 is in contact with the oblique plane 48. As the distal end is forced against the oblique plane, due to the incline of the oblique plane 48, the distal end of the locking plug applies force against the oblique plane to direct the drill bit in an upward direction, driving the shoulder into tight abutment with the lower chuck wall. Thus, once attached, the locking plug insures this tight abutment with the lower chuck wall.

The same procedure is undertaken with the attachment of the second drill bit within the second chuck. Again, the locking plug 42′ in cooperation with the oblique plane 48′ insures that the shoulder 47′ is in tight abutment with the lower chuck wall 38′. As the two chuck walls 38, 38′ are coplanar within tight tolerances, the drill bits (which are identical) are correctly mated to the respective one of the chucks. Thus, shape and configuration of the adjacent chamfers or countersinks will be substantially identically formed.

The upper component 14 is shown as comprising outer surround 30. The outer surround 30 is mounted to the central chuck 20 and generally surrounds the first and second chucks 22, 24. In the configuration shown, the upper component generally comprises a hoop-like cylindrical configuration. The outer surround 30 includes outer surface 32 that terminates at a lower stop surface 34. An outer shroud 36 depends from the outer surface of the outer surround and extends beyond the lower stop surface 34.

The lower component includes central body 50, outer ring 66 and locking tab 68. The central body 50 includes upper end 52, lower end 54, first drill bore 56, second drill bore 58 and outer surface 60. The drill bores extend from the upper end and terminate at the lower end and are aligned with the first and second chucks 22, 24 so as to allow the drill bits 26, 28 to extend therethrough and to be rotatable therewithin. Toward the lower end, opposing side slots 63 provide access to the lower end of the bores. Lubricant or other fluids can be directed into these slots so as to provide lubrication during the drilling process. Additionally, rear openings 65 (FIG. 8) may be present that provide a visual confirmation of the presence or absence of a drill bit, or the position of the drill bit. Such visual inspection can be made by a user manually, or thorough automated equipment.

The outer surface further includes threads 62 that extend about the central body toward the upper end 52 thereof. Additionally, a plurality of vertical channels or slots 64 a are disposed at predetermined spaced intervals along the outer surface 60 of the central body, such that the threads are preferably positioned between the upper ends of the slots and the upper end 52 of the central body.

Outer ring 66 extends about the central body 60 proximate the upper end 52. The outer ring 66 includes inner surface 70, upper stop 71, outer surface 72 and bores, such as bore 74. The outer ring is configured so as to be able to nest within the outer shroud 36 of the outer surround 30. The upper stop 71 is configured to align with the lower stop surface 34 of the outer surround 30. Threads 75 are disposed on the inner surface 70 which matingly engage with the threads 62 of the outer surface of the central body. The bores extend axially through the outer ring at predetermined arcuate positions in a spaced apart orientation about the outer ring. Grasping channels or surfaces are disposed along the outer surface so as to facilitate grasping and retention of the same by the user.

A plurality of axially slidable, and inwardly biased, locking tabs 68 extend through the bores 74 so as to interface with the vertical channels 64 of the outer of the central body 50. It will be understood that the interface between the locking tabs 68 and the vertical channels 64 releasably secure the outer ring to the central body and preclude relative rotation therebetween. A user can overcome the biasing of the locking tabs and rotate the outer ring relative to the central body to translate one relative to the other about the interaction between threads 62 and threads 75. Relative movement in one direction traverses the outer ring along the central body in a first direction whereas relative movement in an opposite direction traverses the outer ring along the central body in a second direction.

The coupling assembly 18 is structurally configured to facilitate the slidable upward and downward movement of the lower component 16 relative to the upper component 14. In the configuration shown, the coupling assembly 18 includes slidable couplings, such as slidable couplings 80 and biasing members 82 which are configured to bias the lower component 16 away from the upper component 14. In the configuration shown, a total of four slidable couplings are provided, and a pair of gas elements to provide the downward biasing. These slidable couplings allow for vertical movement while precluding side to side movement or rotational movement relative to the chuck base.

With reference to FIG. 5, the lower drill tool is shown generally at 11 as being in alignment with the upper drill tool. The lower drill tool includes lower base 92 and upper portion 94. The upper portion 94 is slidably mounted to the lower base 92, and terminates at a part receiving surface. A lower biasing member 96 biases the upper portion 94 away from the lower base 92. The lower biasing member 96 directs a stronger biasing force of the upper portion 94 away from the lower base 92 than the force exerted by the biasing member 82 directing the lower component 16 away from the upper component 14. A sensor 97 (such as, for example) an LVDT, among other sensors is positioned within the lower drill tool to sense downward movement of the upper portion 94 against the lower base 92. As will be explained, such movement indicates that the lower component has bottomed out against the upper component 14 and that the drill bits have completed drilling.

In operation, the user first attaches the correct desired drill bits to the first chuck and the second chuck. In many aircraft applications, wherein fastener hardware is attached to a bracket with rivets, the openings formed in the bracket by the drill bits are chamfered or countersunk openings. And, the shape and depth of the countersink is dimensionally significant, having very tight tolerances. As such, the depth at which the drill bit extends through the bracket becomes a very tightly controlled operation to achieve such tolerances.

Once the drill bits are provided and the entire upper drill tool is attached to the press (FIG. 2), the user can determine the travel of the lower component 16 relative to the upper component 14 which determines the amount of the drill bits that extend beyond the lower end of the central body of the lower component, and, in turn, the interaction of the drill bit with the bracket. As the drill bits are longitudinally fixed to the chuck base and the upper component, as the lower component is directed toward the upper component, the lower end of the drill bits is directed toward the lower end of the central body of the lower component, and eventually beyond the lower end of the central body.

With reference to FIGS. 9 through 11, the movement of the lower component stops relative to the upper component when the upper stop 71 of the lower component contacts the lower stop surface 34 of the upper component. This defines the upper range of movement of the upper component relative to the lower component (i.e., the stroke). This, in turn, defines the depth of the drill bit (i.e., the amount of the drill bit that extends beyond the lower end of the central body of the lower component).

To adjust the amount of the protrusion of the drill bit beyond the lower end of the central body of the lower component, the user can rotate the outer ring relative to the central body. As noted above, rotating in a first direction adjusts the ring toward the upper end of the central body, and thereby, shortening the stroke of the lower component. A shorter stroke exposes less of the drill bits (and decreases the depth of the chamfer, on bits forming a chamfer). On the other hand, rotating the outer ring relative to the central body in a second direction (opposite of the first direction) directs the ring away from the top end of the central body, and thereby, increasing or lengthening the stroke of the lower component (and increasing the depth of the chamber, on bits forming a chamfer).

To facilitate controlled movement of the central body relative to the outer ring, as the user starts to apply force to rotate the outer ring relative to the central body, the user must first overcome the force of the locking tab against the vertical channels. The movement force directs the locking tabs to retract (overcoming the inward axial bias thereof) from within the respective vertical channels. Once the locking tabs have been pushed outwardly, further application of force will allow the ring to be rotated relative to the central body (which is precluded from rotation relative to the central chuck). The user can proceed through successive engagements and disengagements (i.e., interfaces) between the locking tabs with respective ones of the vertical channels until the desired stroke is reached (that is, the desired depth of protrusion of the drill bits beyond the lower end of the central body). In the configuration shown, the movement of a locking tab from a vertical channel to an adjacent vertical channel represents a change in the protrusion of the drill bits beyond the central body of one thousandth of an inch (with the understanding that it is a greater protrusion when relatively rotated in a first direction, and a lesser protrusion when relatively rotated in a second direction). Of course, the incremental rotations may adjust the stroke by more or less than one thousandth of an inch, and different increments are contemplated, both larger and smaller.

Once the desired stroke (i.e., distance that the drill bits extend beyond the lower end of the central body) has been set, the user is ready to drill and form openings in a bracket. Initially, the upper tool 10 is directed in a downward direction toward the bracket which is positioned on the lower tool 11. Eventually, the bracket is reached and further movement of the lower component ceases while the upper component and the central chuck are permitted to continue moving in a downward direction. This continued movement eventually introduces the distal ends of the drill bits (which are spinning) to the bracket and the further movement forms the openings in the bracket. With reference to FIGS. 10 and 11, eventually, the upper stop 71 of the outer ring reaches and contacts the lower stop surface 34 of the outer surround 30. The drill bit is precluded from extending further beyond the lower end of the central body, and the openings have been completed (the end of the stroke has been reached).

Referring again to the configuration of the two tools in FIG. 5, any continued movement downward by the upper drill tool relative to the lower drill tool overcomes the lower biasing member 96 and the upper portion 94 of the lower tool begins to move relative to the lower base 92. The sensor senses this movement and directs the upper drill tool to stop moving in a downward direction. The upper drill tool can then retract completing the drilling of the openings.

In other configurations, the lower drill tool may be stationary, and the system can sense an increased current to the motors or servos that are directing the upper drill tool toward the lower drill tool. Once sensed, the upper drill tool can stop moving in the downward direction. The upper drill tool can then retract completing the drilling of the openings.

Throughout the process, lubricant can be directed through the side slots 63 (FIGS. 7 and 8) to insure proper lubrication and cooling during the drilling operation. In addition, a sensor (optical, for example) can be directed toward the rear openings 65 (FIG. 8) to ensure that the drill bits are not broken, or damaged or missing, and may be utilized to determine the condition of the drill bits.

It will be understood that the upper and lower drill tools can be releasably coupled to the overall system of the drill portion (FIG. 2) or the overall system 500 (FIG. 1) Separate upper drill tools and lower drill tools may be utilized to provide for different pitch, opening size, opening depth, drill bit spacing among other differences.

The foregoing description merely explains and illustrates the disclosure and the disclosure is not limited thereto except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications without departing from the scope of the disclosure. 

What is claimed is:
 1. A central chuck comprising: a chuck base; a first chuck rotatably coupled to the chuck base, the first chuck having: a chuck bore terminating at a lower chuck wall; a transverse locking bore extending transversely into the chuck bore spaced apart from the lower chuck wall, the transverse locking bore being threaded; a locking plug threaded into the transverse locking bore, the locking plug thread terminating at a distal end, wherein rotation in a first direction advances the locking plug thread into the bore and rotation in a second direction retreats the locking plug thread from within the bore; and a first drill bit, the first drill bit having an upper portion, a central portion and a distal end, wherein the upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion, and, with an oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder, whereupon insertion of the upper portion of the first drill bit into the chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond, and with the distal end of the locking plug directable at and into contact the oblique plane whereupon further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.
 2. The central chuck of claim 1 further comprising: a second chuck rotatably coupled to the chuck base, the second chuck having: a chuck bore terminating at a lower chuck wall; a transverse locking bore extending transversely into the chuck bore spaced apart from the lower chuck wall, the transverse locking bore being threaded; a locking plug threaded into the transverse locking bore, the locking plug thread terminating at a distal end, wherein rotation in a first direction advances the locking plug thread into the bore and rotation in a second direction retreats the locking plug thread from within the bore; and a second drill bit, the first drill bit having an upper portion, a central portion and a distal end, wherein the upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion, and, with an oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder, whereupon insertion of the upper portion of the second drill bit into the second chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond, and with the distal end of the locking plug directable at and into contact the oblique plane whereupon further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.
 3. The central chuck of claim 2 wherein the lower chuck wall of the first chuck and the lower chuck wall of the second chuck are coplanar.
 4. The central chuck of claim 2 wherein each of the first drill bit and the second drill bit are substantially identical, and wherein the first drill bit and the second drill bit each include a chamfer or countersink formed between the central portion and the distal end.
 5. The central chuck of claim 1 wherein the first drill bit further includes a chamfer or countersink formed between the central portion and the distal end.
 6. The central chuck of claim 1 wherein the oblique plane of the first drill bit is angled relative to a plane tangent to an outer surface of the upper portion in an inward and downward direction toward the shoulder at an angle of between approximately 3° and 17°
 7. The central chuck of claim 6 wherein the angle is approximately 4° and 12°, and more preferably approximately 6° and 9° and more preferably between 7° and 8°.
 8. The central chuck of claim 1 wherein each of the upper portion and the central portion of the first drill bit comprise cylindrical configurations that are concentric.
 9. The central chuck of claim 1, wherein the shoulder is perpendicular to a longitudinal axis of the first drill bit.
 10. An upper drill tool comprising: central chuck comprising: a chuck base; a first chuck rotatably coupled to the chuck base, the first chuck having: a chuck bore terminating at a lower chuck wall; a transverse locking bore extending transversely into the chuck bore spaced apart from the lower chuck wall, the transverse locking bore being threaded; a locking plug threaded into the transverse locking bore, the locking plug thread terminating at a distal end, wherein rotation in a first direction advances the locking plug thread into the bore and rotation in a second direction retreats the locking plug thread from within the bore; and a first drill bit, the first drill bit having an upper portion, a central portion and a distal end, wherein the upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion, and, with an oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder, whereupon insertion of the upper portion of the first drill bit into the chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond, and with the distal end of the locking plug directable at and into contact the oblique plane whereupon further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall; an upper component coupled to the central chuck, the upper component having a lower stop surface; a lower component having: a central body with an outer surface, the outer surface having threads disposed thereon, the central body having a drill bit bore corresponding to each of the at least one chuck, to facilitate the passage of the drill bit therethrough, the bore terminating at a lower end of the central body; and an outer ring having an inner surface, with the inner surface having outer ring threads positioned thereon, the outer ring threads matingly engaging the threads of the central body, the outer ring having an upper stop interfaceable with the lower stop surface of the upper component; and a coupling assembly having a slidable coupling having a first end attached to the lower component and a second end attached to one of the central chuck and the upper component, the slidable coupling facilitating the slidable movement of the lower component from a first orientation wherein the upper stop is spaced apart from the lower stop surface and a second orientation wherein the upper stop is in abutting engagement with the lower stop surface, with the first orientation and the second orientation defining a stroke.
 11. The upper drill tool of claim 10 further comprising: a second chuck rotatably coupled to the chuck base, the second chuck having: a chuck bore terminating at a lower chuck wall; a transverse locking bore extending transversely into the chuck bore spaced apart from the lower chuck wall, the transverse locking bore being threaded; a locking plug threaded into the transverse locking bore, the locking plug thread terminating at a distal end, wherein rotation in a first direction advances the locking plug thread into the bore and rotation in a second direction retreats the locking plug thread from within the bore; and a second drill bit, the first drill bit having an upper portion, a central portion and a distal end, wherein the upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion, and, with an oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder, whereupon insertion of the upper portion of the second drill bit into the second chuck bore, the shoulder interfaces with the lower chuck wall to limit insertion therebeyond, and with the distal end of the locking plug directable at and into contact the oblique plane whereupon further threaded insertion of the locking plug into the chuck bore directs the drill bit in an upward direction and forces the shoulder into tight abutment with the lower chuck wall.
 12. A drill bit for use in association with a central chuck, the drill bit comprising: an upper portion, a central portion; and a distal end, wherein the upper portion has a smaller diameter than the central portion with a shoulder spanning between the upper portion and the central portion, and, with an oblique plane defined in the upper portion inclined in a downward and inward direction toward the shoulder.
 13. The drill bit of claim 12 further comprising a chamfer or countersink formed between the central portion and the distal end.
 14. The drill bit of claim 12 wherein the oblique plane of the first drill bit is angled relative to a plane tangent to an outer surface of the upper portion in an inward and downward direction toward the shoulder at an angle of between approximately 3° and 17°
 15. The drill bit of claim 14 wherein the angle is approximately 4° and 12°, and more preferably approximately 6° and 9° and more preferably between 7° and 8°.
 16. The drill bit of claim 14 wherein each of the upper portion and the central portion of the first drill bit comprise cylindrical configurations that are concentric.
 17. The drill bit of claim 12, wherein the shoulder is perpendicular to a longitudinal axis of the first drill bit.
 18. The drill bit of claim 12 wherein the distal end has a diameter that is smaller then a diameter of the upper portion.
 19. The drill bit of claim 12 wherein the oblique plane terminates at the shoulder and initiates spaced apart from an upper end of the upper portion. 